Users with `create` but not `override` privileges can perform local sync

Overview

Impact

"Local sync" is an Argo CD feature that allows developers to temporarily override an Application's manifests with locally-defined manifests. Use of the feature should generally be limited to highly-trusted users, since it allows the user to bypass any merge protections in git.

An improper validation bug allows users who have create privileges but not override privileges to sync local manifests on app creation. All other restrictions, including AppProject restrictions are still enforced. The only restriction which is not enforced is that the manifests come from some approved git/Helm/OCI source.

The bug was introduced in 1.2.0-rc1 when the local manifest sync feature was added.

Patches

The bug has been patched in the following versions:

• 2.10.3
• 2.9.8
• 2.8.12

Workarounds

To immediately mitigate the risk of branch protection bypass, remove applications, create RBAC access. The only way to eliminate the issue without removing RBAC access is to upgrade to a patched version.

Branch protection rules and review requirements are a great way to enforce security constraints in a GitOps environment, but they should be just one layer in a multi-layered approach. Make sure your AppProject and RBAC restrictions are as thorough as possible to prevent a review bypass vulnerability from permitting excessive damage.

References

• Argo CD RBAC documentation

For more information

• Open an issue in the Argo CD issue tracker or discussions
• Join us on Slack in channel #argo-cd

Affected packages

• github.com/argoproj/argo-cd >= 1.2.0-rc1, <= 1.8.7
• github.com/argoproj/argo-cd/v2 >= 2.9.0, < 2.9.8
• github.com/argoproj/argo-cd/v2 >= 2.10.0, < 2.10.3
• github.com/argoproj/argo-cd/v2 >= 2.0.0-rc3, < 2.8.12

Remediation

Upgrade to a patched release:

• github.com/argoproj/argo-cd/v2 2.9.8
• github.com/argoproj/argo-cd/v2 2.10.3
• github.com/argoproj/argo-cd/v2 2.8.12